Effect of intracellular free calcium mobilization on aggregation of umbilical cord blood platelets.

Aggregation activity of platelets in umbilical blood is lower than that in adult blood, but the reason for this is not well understood. It has recently been clarified that calcium plays a role as a second messenger of platelet aggregation, and that glycoproteins of platelet surface membrane such as glycoprotein I b and IIb/IIIa are receptors for agonists inducing aggregation. We examined the concentrations of intracellular calcium and the membrane glycoproteins of platelets in umbilical and adult blood. The increase of intracellular calcium in umbilical platelets was lower than that in adult platelets when the aggregation was induced by ADP, collagen, thrombin and epinephrine. Only calcium ionophore A23187 induced aggregation of both umbilical and adult platelets. On the other hand, there were no qualitative differences between glycoproteins I b and IIb/IIIa of these two groups. Therefore, the low aggregation activity of umbilical platelets seems to be due to low responsiveness of the intracellular calcium system, not to the disorder of functional surface membrane glycoprotein.

[Pharmacokinetic and clinical studies on cefodizime in the field of obstetrics and gynecology].

We have conducted pharmacokinetic and clinical trials of a new cephem derivative, cefodizime (THR-221, CDZM), and obtained the following results. 1. We administered CDZM to 4 cases with abdominal simple hysterectomy due to myoma uteri at a dose level of 1 g by drip intravenous injection and studied average levels of transfer measured at various locations in the uterine tissues and adnexa at an average of 2 hours after administration. CDZM level was highest in the oviduct, 13.7 micrograms/g (ratio with respect to the uterine arterial blood: 91.3%), followed by the ovary, portio vaginalis, cervix uteri and endometrium, and was lowest in the myometrium, 8.3 micrograms/g (55.3%). CDZM concentrations were higher than 6.04 micrograms/g in any tissues. 2. To study CDZM transfer to pelvic cavity fluid, we administered CDZM to 5 cases with total hysterectomy due to cervical cancer of uteri at a dose level of 2 g using drip intravenous injection. The drug was transferred at high levels to the pelvic cavity fluid. A level of 11.7 micrograms/ml was observed at 3 hours after injection. The drug levels in the pelvic cavity fluid were maintained continuously higher levels than those of venous blood. These concentrations in the uterine tissues and pelvic cavity fluid were higher than the MIC against many strains of Gram-positive and Gram-negative bacteria, hence we considered them to be therapeutically effective concentrations. 3. Eleven cases of gynecological infections receiving in totals of 8 to 48 g of CDZM demonstrated "excellent" results in 3 cases, "good" in 8 cases. Eight strains of organisms were isolated from 10 cases.(ABSTRACT TRUNCATED AT 250 WORDS)